﻿Shader "Particles/Additive" {
	Properties{
		_TintColor("Tint Color", Color) = (0.5,0.5,0.5,0.5)
		_MainTex("Particle Texture", 2D) = "white" {}
	_InvFade("Soft Particles Factor", Range(0.01,3.0)) = 1.0
	}

		Category{
		Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" }
		Blend SrcAlpha One
		AlphaTest Greater .01
		ColorMask RGB
		Cull Off Lighting Off ZWrite Off Fog{ Color(0,0,0,0) }
		BindChannels{
		Bind "Color", color
		Bind "Vertex", vertex
		Bind "TexCoord", texcoord
	}

		// ---- Fragment program cards
		SubShader{
		Pass{

		CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#pragma multi_compile_particles

#include "UnityCG.cginc"

		sampler2D _MainTex;
	fixed4 _TintColor;

	struct appdata_t {
		float4 vertex : POSITION;
		fixed4 color : COLOR;
		float2 texcoord : TEXCOORD0;
	};

	struct v2f {
		float4 vertex : POSITION;
		fixed4 color : COLOR;
		float2 texcoord : TEXCOORD0;
#ifdef SOFTPARTICLES_ON
		float4 projPos : TEXCOORD1;
#endif
	};

	float4 _MainTex_ST;

	v2f vert(appdata_t v)
	{
		v2f o;
		o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
#ifdef SOFTPARTICLES_ON
		o.projPos = ComputeScreenPos(o.vertex);
		COMPUTE_EYEDEPTH(o.projPos.z);
#endif
		o.color = v.color;
		o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
		return o;
	}

	sampler2D _CameraDepthTexture;
	float _InvFade;

	fixed4 frag(v2f i) : COLOR
	{
#ifdef SOFTPARTICLES_ON
		float sceneZ = LinearEyeDepth(UNITY_SAMPLE_DEPTH(tex2Dproj(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos))));
	float partZ = i.projPos.z;
	float fade = saturate(_InvFade * (sceneZ - partZ));
	i.color.a *= fade;
#endif

	return 2.0f * i.color * _TintColor * tex2D(_MainTex, i.texcoord);
	}
		ENDCG
	}
	}

		// ---- Dual texture cards
		SubShader{
		Pass{
		SetTexture[_MainTex]{
		constantColor[_TintColor]
		combine constant * primary
	}
		SetTexture[_MainTex]{
		combine texture * previous DOUBLE
	}
	}
	}

		// ---- Single texture cards (does not do color tint)
		SubShader{
		Pass{
		SetTexture[_MainTex]{
		combine texture * primary
	}
	}
	}
	}
}